/* Visual primitives retained from the original marketing and pixel styles. */
:root {
  color-scheme: light;
  --canvas: #fbf7ed;
  --paper: #fffdf7;
  --surface: #fff;
  --ink: #102347;
  --text: #26354d;
  --muted: #596579;
  --line: #e7e1d5;
  --blue: #2673dd;
  --blue-active: #185aba;
  --sky: #eaf3ff;
  --radius-card: 20px;
  --radius-control: 12px;
  --shadow-card: 0 5px 0 rgba(16,35,71,.12), 0 12px 28px rgba(16,35,71,.06);
  --shadow-button: 0 4px 0 rgba(16,35,71,.18);
  font-family: Pretendard, "Noto Sans KR", "Apple SD Gothic Neo", system-ui, sans-serif;
  font-synthesis: none;
}
* { box-sizing: border-box; }
html { scroll-padding-top: 24px; }
body { margin: 0; color: var(--text); background-color: var(--canvas); background-image: linear-gradient(rgba(38,115,221,.035) 1px, transparent 1px), linear-gradient(90deg,rgba(38,115,221,.035) 1px, transparent 1px); background-size: 16px 16px; font-size: 16px; line-height: 1.7; overflow-wrap: anywhere; }
button, input, textarea { font: inherit; }
button, a, summary { -webkit-tap-highlight-color: transparent; }
a { color: var(--blue-active); text-underline-offset: 4px; }
a:hover { text-decoration-thickness: 2px; }
button, summary { cursor: pointer; }
button:disabled { cursor: default; }
button:focus-visible, a:focus-visible, summary:focus-visible, textarea:focus-visible, input:focus-visible { outline: 3px solid var(--blue); outline-offset: 5px; }
[tabindex="-1"]:focus { outline: none; }
h1, h2, h3, h4 { color: var(--ink); line-height: 1.4; word-break: keep-all; letter-spacing: -.025em; margin: 0 0 16px; }
h1 { font-size: clamp(30px, 4vw, 44px); line-height: 1.25; }
h2 { font-size: clamp(23px, 3vw, 29px); }
h3 { font-size: 21px; }
h4 { font-size: 17px; }
p { margin: 0 0 16px; }
img { display: block; max-width: 100%; }
[hidden] { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.skip-link { position: absolute; top: -100px; left: 16px; z-index: 10; padding: 10px 20px; background: white; }
.skip-link:focus { top: 8px; }
.site-header { border-bottom: 3px solid var(--ink); background: var(--paper); box-shadow: 0 4px 0 rgba(16,35,71,.08); }
.nav { width: min(1120px, calc(100% - 40px)); margin: auto; min-height: 80px; display: flex; justify-content: space-between; align-items: center; gap: 24px; }
.brand { display: inline-flex; gap: 12px; align-items: center; color: var(--ink); font-size: 22px; font-weight: 850; text-decoration: none; flex-shrink: 0; letter-spacing: -.04em; }
.brand-mark { width: 38px; height: 38px; display: grid; place-items: center; background: white; border: 3px solid var(--ink); box-shadow: 3px 3px 0 var(--ink); }
.brand-mark img { width: 27px; height: 27px; image-rendering: pixelated; }
.nav-links { display: flex; align-items: center; gap: 28px; white-space: nowrap; }
.nav-links a { color: var(--ink); text-decoration: none; font-size: 15px; font-weight: 700; min-height: 44px; display: inline-flex; align-items: center; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--blue-active); text-decoration: underline; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 10px; min-height: 48px; padding: 10px 20px; border: 3px solid var(--ink); color: var(--ink); background: white; text-decoration: none; font-weight: 750; text-align: center; line-height: 1.5; border-radius: var(--radius-control); transition: transform 100ms ease, box-shadow 100ms ease, background 100ms ease; }
.button.primary { background: var(--blue-active); color: white; box-shadow: var(--shadow-button); }
.button.primary:hover { background: var(--blue); transform: translate(-1px, -1px); box-shadow: 0 5px 0 rgba(16,35,71,.18); text-decoration: none; }
.button:active { transform: translate(3px, 3px); box-shadow: none !important; }
.button.secondary { border: 2px solid var(--ink); }
.button.secondary:hover { background: var(--sky); text-decoration: none; }
.text-button { border: 0; padding: 10px 0; background: transparent; color: var(--blue-active); min-height: 44px; font-weight: 650; text-decoration: underline; text-underline-offset: 4px; }
.text-button:disabled { color: var(--muted); text-decoration: none; opacity: .65; }
.eyebrow { font-size: 13px; font-weight: 750; color: var(--blue-active); margin-bottom: 10px; letter-spacing: .015em; }
.muted { color: var(--muted); }
.small { font-size: 14px; }
.quiet-link { font-size: 14px; min-height: 44px; display: inline-flex; align-items: center; gap: 8px; white-space: nowrap; }
.content-page { width: min(1000px, calc(100% - 40px)); margin: 56px auto 80px; min-height: 55vh; }
.page-intro { margin-bottom: 32px; max-width: 740px; }
.page-intro > p:not(.eyebrow) { font-size: 18px; color: var(--muted); }
.quiz-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 24px; }
.quiz-card { min-width: 0; padding: 26px; border: 2px solid var(--ink); border-radius: var(--radius-card); box-shadow: var(--shadow-card); background: white; display: flex; flex-direction: column; }
.quiz-card h2 { font-size: 23px; }
.quiz-card > p:not(.eyebrow) { color: var(--muted); flex-grow: 1; }
.card-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 16px; margin-top: 12px; font-size: 14px; }
.card-actions > a:not(.button) { min-height: 44px; display: inline-flex; align-items: center; }
.article { border-radius: var(--radius-card); max-width: 760px; padding: 36px; border: 1px solid var(--line); background: white; }
.article h2 { margin-top: 40px; font-size: 25px; }
.article h3 { margin-top: 24px; }
.article li { margin-bottom: 8px; }
.article p:last-child { margin-bottom: 0; }
.article > h2:first-child { margin-top: 0; }
.definition-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 20px; margin: 28px 0; }
.definition { border-radius: var(--radius-control); padding: 22px; background: var(--sky); border-top: 3px solid var(--blue); }
.definition h3 { margin-top: 0; }
.definition blockquote { margin: 14px 0 0; color: var(--ink); font-weight: 650; }
.callout { border-radius: var(--radius-control); background: var(--paper); border-left: 4px solid var(--blue); padding: 20px; margin: 24px 0; }
.source-list { font-size: 14px; padding-left: 20px; }
.learning-flow { margin: 32px 0; }
.learning-flow > h2 { margin-top: 0; }
.learning-steps { list-style: none; padding: 0; margin: 24px 0 0; }
.learning-steps > li { display: grid; grid-template-columns: 36px minmax(0, 1fr); gap: 16px; padding: 22px 0; margin: 0; border-top: 1px solid var(--line); }
.learning-step-number { border-radius: 50%; display: grid; place-items: center; align-self: start; width: 36px; height: 36px; background: var(--sky); color: var(--blue-active); border: 1px solid var(--blue); font-size: 13px; font-weight: 750; }
.learning-steps h3 { margin: 2px 0 10px; font-size: 20px; }
.learning-steps blockquote { margin: 0 0 12px; color: var(--ink); font-size: 18px; font-weight: 700; line-height: 1.7; word-break: keep-all; }
.learning-steps p { margin-bottom: 0; }
.learning-overview { max-width: 760px; }
.concept-list-title { margin: 44px 0 24px; }
.concept-footnote { margin-top: 36px; max-width: 760px; }
.concept-footnote p { margin-top: 8px; }
.everyday-practice { border-radius: var(--radius-control); margin: 40px 0; padding: 28px; background: var(--paper); border: 1px solid var(--line); border-top: 3px solid var(--blue); }
.everyday-practice > .learning-flow { margin: 12px 0 24px; }
.everyday-practice > .learning-flow > h2 { margin-top: 0; }
.reflection-questions { padding-left: 22px; }
.practice-takeaway { margin-top: 20px; color: var(--blue-active); font-weight: 650; }
.about-concepts { padding-left: 20px; }
details { border-top: 1px solid var(--line); }
summary { padding: 18px 0; color: var(--ink); font-weight: 700; }
details > div { padding: 0 0 20px; }
.site-footer { border-top: 1px solid var(--line); background: rgba(255,253,247,.8); }
.footer-inner { width: min(1120px, calc(100% - 40px)); margin: auto; padding: 28px 0; display: flex; justify-content: space-between; gap: 28px; align-items: flex-start; font-size: 12px; color: var(--muted); }
.footer-inner p { max-width: 560px; margin: 0 0 8px; }
.footer-links { display: flex; gap: 4px 18px; flex-wrap: wrap; justify-content: flex-end; }
.footer-links a { color: var(--muted); min-height: 36px; display: inline-flex; align-items: center; }
.preference { border-radius: var(--radius-control); padding: 20px; background: var(--sky); margin: 24px 0; }
.preference label { display: flex; align-items: center; gap: 12px; min-height: 44px; font-weight: 700; }
.preference input { width: 20px; height: 20px; }
textarea { display: block; width: 100%; padding: 12px; border: 2px solid var(--ink); background: white; margin-top: 12px; color: var(--ink); }
@media (max-width: 850px) { .quiz-grid { grid-template-columns: 1fr; } .quiz-card { padding: 24px; } }
@media (max-width: 600px) {
  .nav { width: calc(100% - 24px); min-height: 66px; gap: 10px; flex-wrap: nowrap; padding: 10px 0; }
  .brand { font-size: 18px; gap: 8px; }
  .brand-mark { width: 28px; height: 28px; }
  .brand-mark img { width: 20px; height: 20px; }
  .nav-links { gap: clamp(8px, 2vw, 12px); width: auto; justify-content: flex-end; }
  .nav-links a { font-size: 12px; min-height: 44px; }
  .content-page { margin-top: 32px; }
  .article { padding: 24px 20px; }
  .definition-grid { grid-template-columns: 1fr; gap: 12px; }
  .learning-steps > li { grid-template-columns: 30px minmax(0, 1fr); gap: 12px; padding: 20px 0; }
  .learning-step-number { border-radius: 50%; width: 30px; height: 30px; font-size: 12px; }
  .learning-steps blockquote { font-size: 17px; }
  .everyday-practice { border-radius: var(--radius-control); padding: 20px 14px; margin-inline: -6px; }
  .footer-inner { flex-direction: column; gap: 8px; }
  .footer-links { justify-content: flex-start; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; } }

.concept-guide { margin-bottom: 36px; }
.concept-guide > h2 { margin-top: 0; }
.concept-examples { display: grid; gap: 12px; margin: 24px 0; }
.concept-examples > article { padding: 20px; border-radius: var(--radius-control); background: var(--sky); }
.concept-examples h3 { margin: 0 0 8px; font-size: 16px; color: var(--blue-active); }
.concept-examples blockquote { margin: 0 0 10px; color: var(--ink); font-size: 18px; font-weight: 700; word-break: keep-all; }
.concept-examples p { margin: 0; font-size: 14px; }

@media (max-width: 360px) { .nav .brand-mark { display: none; } }

.quiz-category { margin-bottom: 44px; }
.quiz-category > h2 { font-size: 23px; margin-bottom: 8px; }